辐射诱导基因LRIGx的细胞周期特异性表达及编码产物同源性分析

低剂量辐射诱导表达新基因LRIGx被克隆 .Northern印迹杂交结果表明 ,在 0 2Gyγ射线照射后 2～ 4h ,人A5 4 9细胞中该基因mRNA表达水平显著上调 .当照射剂量增加到 2Gy时 ,其诱导表达水平明显低于 0 2Gy照射 .通过细胞周期同步化 ,观察到LRIGx基因表达高峰在G2 M期 .同源性比较和功能保守域分析结果显示 ,该基因编码产物与DNA修复和重组蛋白RAD5 4、ERCC 6 ,染色质重构和转录调节功能蛋白SWI2 SNF2等有同源性 ,其N端具有与染色质重构、基因转录调控和DNA修复有关的 3个功能结构域 ,即CHROMO、SNF2N和解旋酶C端结构域     

生态工程实施对羌塘和三江源国家级自然保护区植被净初级生产力的影响

为了有效评估生态工程建设对青藏高原典型国家级自然保护区的影响, 基于表征生态系统功能状况的植被净初级生产力变化系列数据, 采用样区对比法系统分析了羌塘和三江源两个国家级自然保护区建立及2004/2005年实施的新生态工程的效果。研究表明: (1) 1982-2009年间, 在10组对比样区中有9组保护区内样区的草地净初级生产力呈波动上升的趋势; (2) 2004年后新生态工程的实施效果良好, 有8组对比样区生态状况转好; (3)在所有高寒草地类型中, 新生态工程对高寒草甸类型样区的保护效果最为显著。     

Precursors of three unique cysteine-rich peptides from the scorpion Buthus martensii Karsch

Scorpion venoms contain a large number of small peptides with diverse primary structures and unique pharmacological functions. From a cDNA library prepared from venom glands of the Chinese scorpion Buthus martensii Karsch, clones encoding precursors of three unique cysteine-rich peptides named BmTXKS3, BmTXLP2 and BmAP1 have been isolated and sequenced. These precursors are composed of 54, 94 and 89 amino acids, respectively, containing a signal peptide in their N-termini. Sequence analysis shows that BmTXKS3 and BmTXLP2 are two novel members of a scorpion toxin family sharing cysteine-stabilized α-helical folds. BmAP1 possesses a distinctive cystine framework, which is similar to some serine protease inhibitors and the segments of several extracellular proteins.     

Appraisal of the electrical octet method for estimating earthworm populations in arable land

Quantitative methods are needed for the assessment of the size and composition of earthworm communities. A poorly documented electrical sampling method, Thielemann's octet method, was compared with two long‐established methods, formalin extraction and soil hand sorting, in conventional and direct‐drilled wheat cropping systems at two sites with medium to heavy textured soils in Ireland. Under all agronomic conditions tested, the electrical method extracted significantly higher earthworm numbers than formalin, but earthworm biomasses were not significantly different. When used routinely over two years during periods of high earthworm activity, the electrical method yielded community estimates that were comparable in both size and species composition to those obtained by soil hand sorting (25 cm depth), except in recently ploughed land. However, Murchieona minuscule, a minute endogeic species, was underestimated by electrical extraction. It is concluded that the electrical octet method can be a reliable and useful alternative to other dynamic methods for estimating earthworm populations, especially in situations where minimum soil disturbance is desirable.     

Camps 2.0: exploring the sequence and structure space of prokaryotic, eukaryotic, and viral membrane proteins

Structural bioinformatics of membrane proteins is still in its infancy, and the picture of their fold space is only beginning to emerge. Because only a handful of three-dimensional structures are available, sequence comparison and structure prediction remain the main tools for investigating sequence-structure relationships in membrane protein families. Here we present a comprehensive analysis of the structural families corresponding to α-helical membrane proteins with at least three transmembrane helices. The new version of our CAMPS database (CAMPS 2.0) covers nearly 1300 eukaryotic, prokaryotic, and viral genomes. Using an advanced classification procedure, which is based on high-order hidden Markov models and considers both sequence similarity as well as the number of transmembrane helices and loop lengths, we identified 1353 structurally homogeneous clusters roughly corresponding to membrane protein folds. Only 53 clusters are associated with experimentally determined three-dimensional structures, and for these clusters CAMPS is in reasonable agreement with structure-based classification approaches such as SCOP and CATH. We therefore estimate that ～1300 structures would need to be determined to provide a sufficient structural coverage of polytopic membrane proteins. CAMPS 2.0 is available at http://webclu.bio.wzw.tum.de/CAMPS2.0/.     

Revised 2.3 A structure of porcine pepsin: evidence for a flexible subdomain

A revised three-dimensional crystal structure of ethanol-inhibited porcine pepsin refined to an R-factor of 0.171 at 2.3 A resolution is presented and compared to the refined structures of the fungal aspartic proteinases: penicillopepsin, rhizopuspepsin, and endothiapepsin. Pepsin is composed of two nearly equal N and C domains related by an intra dyad. The overall polypeptide fold and active site structures are homologous for pepsin and the fungal enzymes. The weak inhibition of pepsin by ethanol can be explained by the presence of one or more ethanol molecules, in the vicinity of the active site carboxylates, which slightly alter the hydrogen-bonding network and which may compete with substrate binding in the active site. Structural superposition analysis showed that the N domains aligned better than the C-domains for pepsin and the fungal aspartic proteinases: 107-140 C alpha pairs aligned to 0.72-0.85 A rms for the N domains; 64-95 C alpha pairs aligned to 0.78-1.03 A rms for the C domains. The major structural difference between pepsin and the fungal enzymes concerns a newly described subdomain whose conformation varies markedly among these enzyme structures. The subdomain in pepsin comprises nearly 100 residues and is composed of two contiguous segments within the C domain (residues 192-212 and 223-299). the subdomain is connected, or "hinged," to a mixed beta-sheet that forms one of the structurally invariant, active site psi-loops. Relative subdomain displacements as large as a 21.0 degrees rotation and a 5.9 A translation were observed among the different enzymes. There is some suggestion in pepsin that the subdomain may be flexible and perhaps plays a structural role in mediating substrate binding, determining the substrate specificity, or in the activation of the zymogen.     

Evaluación de las características operativas de la versión 2.2018 del instrumento de evaluación del malestar emocional de la National Comprehensive Cancer Network en pacientes atendidos en el Instituto Nacional de Cancerología,Bogotá

Introduction:

Cancer patients have significant levels of emotional distress. The National Comprehensive Cancer Network (NCCN) developed the distress management tool to quickly assess significant distress in oncological patients who require intervention. For its use in Colombia, we made its cross-cultural adaptation and validation.

Objective:

To determine the operative characteristics of the distress management tool, version 2.2018, in patients seen at the Instituto Nacional de Cancerología (INC) in Colombia.

Materials and methods:

Counting with the authorization from the NCCN, we translated, made the cross-cultural adaptation, and evaluated the operational characteristics of the tool. We included 343 cancer patients seen at the INC, who filled out the cross-culturally adapted instrument. A diagnostic test study was carried out with a semi-structured interview as a reference.

Results:

The patients had an average age of 49.7 years (SD=15) and the majority were women (67%). The instrument had an area under the ROC curve of 0.81 (95% CI: 0.77 - 0.86); its optimal cut-off point was 3.5 approached to 4 when using integers on the scale; its sensitivity was 0.81 (95% CI: 0.76 - 0.85), and its specificity, 0.69 (95% CI: 0.64 - 0.74). The agreement percentage between the result of the interview and the instrument was 73% (kappa = 0.64; p< 0.001).

Conclusions:

The distress management tool allowed for the detection of moderate to severe distress requiring intervention and management. This instrument was adapted and validated in cancer patients in Colombia keeping the cutoff point at ≥ 4 as in the original version.     

Comparison of t-tests for differences in sexual dimorphism between populations

A t-test that can be used for evaluating the significance of differences in metric sexual dimorphism between populations is derived directly from mathematical considerations of the differences between distributions. It is compared with the t-test derived by Relethford and Hodges (1985), which was based upon linear regression with sex as a dummy variable. Both are determined to be mathematically equivalent, though the one derived here is more similar in form to traditional t-tests of differences and therefore may be simpler to employ. Both tests require only summary statistics for comparisons between populations and comparisons between generations within populations.